1. Field of the Invention
The present invention relates to a pixel unit structure and a manufacturing method thereof, and more specifically, the present invention relates to a pixel unit structure with a display medium module and a manufacturing method thereof.
2. Description of the Prior Art
With the advancement of technology, users are getting more demanding about visual display and require display devices with the advantages of compactness, excellent display quality, large-sized panel, high color saturation, low cost and low power consumption.
Existing display devices may be categorized into self-luminous and non-self-luminous ones. Liquid crystal display (LCD) devices are one of the primary non-self-luminous flat panel display devices, wherein the amount of light passing through a liquid crystal medium is modulated by controlling the voltage of the upper and lower electrodes of the liquid crystal medium. The effect of color display is achieved with further employment of a color filter layer, a polarizer and some optical films.
Self-luminous flat panel display devices may be categorized into field emissive display, plasma display, electroluminescent display, organic light-emitting diode display and so on. In an organic light-emitting diode display (OLED), light-emitting polymers are deposited between an upper electrode layer and a lower electrode layer. With further employment of a conductive layer of electrons and holes, light is generated by means of an external electric field which moves the carriers and causes the electrons and holes to re-combine. In comparison, an organic light-emitting diode display device is characterized by its wide viewing angle, fast responding speed, thin panel and flexibility; further, it requires neither backlighting nor color filter and may be made large-sized.
The display panel of both LCD and OLED devices has a plate of transparent glass for a substrate, directly forming a thin-film transistor, a lower electrode layer, a display medium layer, an upper electrode layer and others thereon. The thin-film transistor may control the voltage or current imposed on the upper electrode layer and/or the lower electrode layer to control the state of the display medium.
However, a glass substrate may not endure a high annealing temperature (the strain temperature of glass being around 650° C.). Therefore, the manufacturing process of the foregoing elements has to be performed at a relatively low temperature. This may cause a low mobility rate of electron in the thin-film transistor, which means a larger-sized transistor is required for providing sufficient charging ability.
Further, the larger the size of the glass substrate, the larger the area of the thin-film transistor formed on the glass substrate (that is, the array of the thin-film transistor has larger dimensions). The manufacturing process of the thin-film transistor will have the disadvantages of expensive equipment, complicated manufacturing process, longer manufacturing time, and unstable mass production quality and yield rate. Therefore, a large-dimensioned array of thin-film transistor is harder to manufacture and its manufacturing cost is higher.
In view of the foregoing, existing display devices still have various disadvantages to overcome.